A novel high current rate SCR for pulse power applications

Novel high-power thyristors with a blocking capability of up to 6 kV and excellent turn-on behaviour are presented. These devices have been investigated as closing switches for very short current pulses as they occur, e.g., with laser applications for very short pulse durations, or with electric launchers for longer pulses at very high di/dt. The maximum current capability of the devices is of the order of a few hundred kiloamps, and the current rise rate can go up to several ten kA/μs. The triggering circuit is arranged directly around the thyristor in order to minimize the parasitic inductance in the gate-cathode loop and to optimize the compactness of the whole switch. In this way a very high gate current can instantaneously be applied, and the device turns on very fast. This is essential for a series connection of devices as well as for a minimization of the turn-on losses. The power needed for the triggering circuit can be supplied by external sources or can be extracted from the main pulse power circuit. The combination of the above high-power thyristor with the low-inductance triggering circuit forms an ideal switch that can be used in a wide range of pulse power applications